"I can't fathom how many tablets will be under those Christmas trees," he said during a keynote presentation at the UBS Global Media and Communications Conference in New York today. "One of the breakthrough years for tablets should be this year."

AT&T is the first company to offer Windows 8 tablets, he said. The company is adding devices based on Microsoft's new OS to its Apple (AAPL) iPad and Google (GOOG) Android offerings.

In October, AT&T unveiled Windows 8 tablets from Asus and Samsung, part of the telecom giant's holiday-season push.

"This is the first time that we have had tablets from all three major OSes," said de la Vega.

Despite some rumblings of discontent with Microsoft's slew of new OSes, de la Vega said: "I'm very excited about what we're seeing from Windows -- the OS is very good," pointing to Nokia(NOK) and HTC phones running Windows Phone 8.

The AT&T Mobility chief said the company's Apple business is "growing faster than ever."

AT&T activated 4.7 million iPhones during its third quarter, but wrestled with inventory constraints of the new iPhone 5.

De la Vega was asked about the recent round of consolidation in the telecom sector, which has seen Softbankacquire a 70% stake in Sprint (S) and MetroPCS (PCS) grabT-Mobile's U.S. operations.

"I think, in the case of Sprint, obviously the Softbank deal recapitalizes the company and gives them a better balance sheet," he replied, but sees no major M&A-driven shifts in the telecom market.

"It doesn't change, in my view, the competitive nature of the industry," he added. "What we see in the U.S. is a highly competitive environment, one that's creating great value for customers."